O2 sensor question
 

My car failed CO part of the California emissioon at 15 mph (4%)but the CO is great at 25 mph (.008 %). The required is about 2%. Do you think O2 sensor can be a problem? Would O2 sensor work intermittently? My logic is that since CO is okay at 25 mph, O2 sensor should be working and my problem would be elsewhere. I have only 39,000 miles and would think my O2 sensor is still okay. Is there any carbon deposit on the tip that I need to clean off? I hate to touch it if I didn't have to. I may crack it and get into more problems than I need - as I usually do. '87 930

I don't have an answer for your CO problem, but can say that the O2 sensor usually lasts at least 60K.

O2 sensor question
 

Mod--did you do the "normal" prep for your smog check, like run some Techron or Progard thru it to

O2 sensor question
 

Whoops! sorry 'bout that--didn't finish my previous post and then hit the wrong button! Any-
how, I was asking whether you had prepared for the test by running some Techron or Progard thru the car to clean up the spritzers, drive it to heat it up good and hot before the test, etc. Also, make sure to ask the tester to check it before he goes online to Sacramento so you don't get caught up in the hassle resulting from a formal "failed Smog"!
From your description, I'm betting on fouled injectors. Good Luck

George 86T

Hi,

if you have a problem with the smog-test then make shure your car (engine and exhaust) are real hot.
Don´t let the engine idle too long... do the test fast after a "hot" ride.

greetings